...because the co-founder in question has been sued for sexual harassment and sexual discrimination.
Whatever the outcome of the case and the irony of the context, there's an important legal principle at play here which founders should take note of.
Simply put harassment (of any kind) at work is behaviour that makes someone feel intimidated or offended.
It's the feelings of the person making the complaint that matter, not the intentions of the person who caused the alleged behaviour.
A company needs to have simple anti-harassment and bullying policies in place as well as a process to deal with grievances.
If all your company has is an employment agreement with no reference to grievances, anti-harassment or bullying, you are at risk. Clearly if there are only two or three people in the company this is a low risk, but as soon as the company grows in size it is prudent to put in place policies.